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Biomedical subjects

A Martens

Publications and source records attributed to A Martens.

At least 19 recordsLinked to original sources
PubMed2006

Surgical repair of a tibial fracture in a Belgian Landrace pig.

This paper reports the surgical treatment of a tibial fracture in a castrated adult male Belgian Landrace pig of 180 kg. The fracture was repaired using an intramedullary Steinmann pin, combined with cerclage wire and external transfixation. In contrast to other animal species, the fracture repair in the pig was hindered by the short and curved bones, the thick subcutaneous fat layer and the pronounced musculature. Postoperatively, the pig developed an osteomyelitis of the tibia due to pin tract contamination. Despite this complication, the fracture healed acceptably when all fixation material was removed two months after surgery. The infection resolved quickly and a satisfactory clinical result was obtained.

Animals↗
PubMed2005

Detection of bovine papillomavirus DNA on the normal skin and in the habitual surroundings of horses with and without equine sarcoids.

The purpose of the present study was to examine whether bovine papillomavirus (BPV) DNA can be detected on the normal skin and in the habitual surroundings of horses with and without equine sarcoids by means of superficially taken swabs. In affected horses, no significant difference in presence of BPV-DNA could be observed between samples obtained from the equine sarcoid surface, from normal skin close to the tumour and from a normal skin site in direct contact with the tumour. From the group of healthy horses living in contact with affected horses, 44% were BPV-DNA positive. The surroundings of affected and non-affected horses are probably not a major source of BPV-DNA contamination. It can be concluded that BPV-DNA is present on the normal skin of horses affected by equine sarcoid and to a lesser degree, on the normal skin of horses living in contact with affected horses.

Animals↗
PubMed2004

Do folic acid and thiocyanate have a preventive effect on exogenously induced disturbances of embryonic cranial development?

The preventive influence of folic acid and thiocyanate on procarbazine-induced disturbances of embryonic cranial development was investigated on experimental animals. Low dosages of folic acid or thiocyanate demonstrated no prophylactic effect. When thiocyanate was administered alone, an increased cleft rate was unexpectedly found for the secondary palate. The combined application of folic acid and thiocyanate showed a cleft-prophylactic effect in the secondary palate in addition to growth protection in the primary palate. It can be assumed that thiocyanate has a positive effect on chondral and osseous growth of the palate during the post-sensitive phase of embryogenesis, while in the sensitive phase, it can function as a carrier for teratogenous and toxic substances.

Animals↗
PubMed2004

Detection of bacterial DNA in synovial fluid from horses with infectious synovitis.

Standard culturing techniques are often unrewarding in confirming diagnosis of synovial infection in the equine patient. Several human studies report the use of sensitive polymerase chain reaction (PCR) techniques for the detection of bacterial involvement in acute synovitis. However, successful extraction of bacterial DNA directly from clinical samples from horses without prior culture has not been reported yet. The goal of this study was to develop a sensitive and reliable method for molecular detection and identification of bacterial species in synovial fluid from horses with infectious synovitis. Synovial fluid samples from 6 horses with culture confirmed synovial infection were used for broad range 16S rRNA gene PCR. Synovial aspirates of 2 healthy horses were used as negative controls. Following extraction and purification of synovial fluid DNA, all samples were processed by touchdown PCR. Amplicons were detected by reverse line blot hybridisation and visualised with chemiluminescence. Pathogen-specific detection of 16S rRNA gene sequences was successful in all 6 synovial fluid samples. No bacterial DNA was detected in the aspirates from the negative control horses using touchdown PCR followed by 25 additional cycles of amplification. The identity of the pathogens was confirmed by DNA sequencing of the amplicons. It can be concluded that broad range 16S rRNA gene PCR followed by reverse line blot hybridisation is a promising technique for detection of bacterial DNA in synovial fluid samples. Further research should aim at the detection of bacterial DNA in synovial fluid samples suspected of infection but having negative culture results. When the 16S PCR proves to be reliable and more sensitive than standard culturing techniques, it may become a powerful tool in the diagnosis of synovial infection.

Animals↗
PubMed2003

[Diagnosis of cystic fibrosis; simple genotyping to rule out the disease preferable to starting with the sweat test].

For historical reasons, the sweat test remains the cornerstone in the diagnostic work-up for cystic fibrosis (CF). If CF is suspected, the sweat test (following pilocarpine iontophoresis) is usually performed first to confirm or rule out the diagnosis of CF. Sweat testing, however, is cumbersome to the patient, prone to technical difficulties and unreliable in young children < 4 weeks as well as in adults because of increasing chloride concentrations with age. False-positive and false-negative results do exist. Simple DNA testing with PCR in peripheral blood for a small number of the most common mutations causing CF, notably the delta F508-mutation in the Dutch population, rules out CF with a likelihood of more than 99%. Because of the high negative predictive value of DNA testing, in combination with its speed, reliability and convenience for the patient, starting the diagnostic work-up for CF with DNA testing can be justified in hospitals which possess the laboratory facilities for this type of test.

Cystic Fibrosis↗
PubMed2001

Evaluation of excision, cryosurgery and local BCG vaccination for the treatment of equine sarcoids.

Ninety-five horses with sarcoids were subjected to three types of treatment: surgical excision (conventional or carbon dioxide laser), cryotherapy or local BCG vaccination. The type of treatment was selected on the basis of the size, location and clinical appearance of the tumours. The choice between conventional and laser excision was empirical. A successful outcome was obtained in 11 of 14 (79 per cent) of the horses treated by cryosurgery, 18 of 27 (67 per cent) treated by BCG vaccination, 18 of 22 (82 per cent) treated by conventional excision, and 20 of 28 (71 per cent) treated with a carbon dioxide laser. For both excision methods, rigorous measures were taken to avoid autoinoculation and to ensure a wide margin of normal skin. The probability of local recurrence after excision was significantly higher for large sarcoids and sarcoids which had previously failed to respond to treatment. In 10 of the 31 horses with remaining sarcoids, some or all of the untreated sarcoids were observed to regress spontaneously.

Animals↗
PubMed2001

PCR detection of bovine papilloma virus DNA in superficial swabs and scrapings from equine sarcoids.

The purpose of this study was to examine if bovine papilloma virus (BPV) DNA can be detected in superficial swabs or scrapings from equine sarcoids. Samples were obtained from 92 sarcoids and 20 non-sarcoidal control lesions. The polymerase chain reaction technique was used with a first primer set to check whether DNA extraction was successful, and with a second primer set specific for BPV-DNA. DNA isolation was successful in 88% of the swabs and 93% of the scrapings. All control lesions were negative for BPV-DNA.

Animals↗
PubMed2001

Ancient diversification of the Pto kinase family preceded speciation in Solanum.

Recent phylogenetic analyses of the nucleotide binding sites (NBS)-leucine-rich repeats (LRR) class of plant disease resistance (R) genes suggest that these genes are ancient and coexist next to susceptibility alleles at resistance loci. Another class of R genes encodes serine-threonine protein kinases related to Pto that were originally identified from wild relatives of tomato. In this study, we exploit the highly diverse genus Solanum to identify Pto-like sequences and test various evolutionary scenarios for Pto-like genes. Polymerase chain reaction amplifications with the use of primers that were developed on the basis of conserved and variable regions of Pto revealed an extensive Pto gene family and yielded 32 intact Pto-like sequences from six Solanum species. Furthermore, Pto-like transcripts were detected in the leaf tissue of all tested plants. The kinase consensus and autophosphorylation sites were highly conserved, in contrast to the kinase activation domain, which is involved in ligand recognition in Pto. Phylogenetic analyses distinguished nine classes of Pto-like genes and revealed that orthologs were more similar than paralogs, suggesting that the Pto gene family evolved through a series of ancient gene duplication events prior to speciation in Solanum. Thus, like the NBS-LRR class, the kinase class of R genes is highly diverse and ancient.

Amino Acid Sequence↗
PubMed2001

"Docs 'n drugs--the virtual polyclinic": an intelligent tutoring system for web-based and case-oriented training in medicine.

Since the beginning of the year 2000 medical students of the University of Ulm are working in their curriculum with the web-based and case-oriented tutoring system "Docs 'n Drugs - The Virtual Polyclinic". The system consists of different subsystems and services. One subsystem is the Training System. It is based on three models: the Tutoring Process Model, the Case Knowledge Model and the Medical Knowledge Model. They describe the tutoring process as a series of nodes and steps, depict the structure of the medical cases, and provide the medical knowledge respectively. Case knowledge and medical knowledge form the expert knowledge of the medical domain. Together with the tutoring process, they build the basis for automatic intelligent tutoring. After giving a deeper insight into the system architecture and the training case structure, an informal evaluation shows a first feedback of the learners.

Clinical Medicine↗
PubMed2000

Partial tibial neurectomy in 113 Belgian blue calves with spastic paresis.

One hundred and thirteen double-muscled Belgian blue calves (69 males and 44 females) with spastic paresis (52 unilateral and 61 bilateral) were treated surgically by partial tibial neurectomy under caudal epidural anaesthesia. Telephone inquiries made at least three-and-a-half months later established that good results were obtained in 83.2 per cent of the calves; a considerable improvement was reported in 4.4 per cent which still had intermittent spastic contractions; severe hyperflexion of the hock necessitating early slaughtering was recorded in 4.4 per cent of the calves; and in 8 per cent there was little or no improvement.

Anesthesia, Epidural↗
PubMed2000

Histopathological characteristics of five clinical types of equine sarcoid.

The purpose of this study was to determine the characteristics of occult, verrucous, fibroblastic, nodular and mixed equine sarcoids. Ten tumours of each type were examined histologically and analysed for the presence of bovine papilloma virus (BPV)- DNA. All tumours were positive for BPV - DNA and showed an increased density of dermal fibroblasts. Epidermal hyperplasia, hyperkeratosis, rete peg and 'picket fence' formation were only found consistently in the verrucous and mixed types and were often not present in occult and nodular sarcoids. Immunohistochemical staining for Keratins 10 and 16, Ki67 and p53 showed no important differences between the clinical types. It can be concluded that the presence of BPV - DNA and the increased density of dermal fibroblasts were the only common characteristics for all sarcoids of the different clinical types. The presence of other microscopic alterations was variable but could not be used in the differentiation of the clinical types based on histology.

Animals↗
PubMed2000

In vitro and in vivo evaluation of hypericin for photodynamic therapy of equine sarcoids.

The therapeutic potential of the photodynamic compound, hypericin, in the treatment of equine sarcoids was evaluated. The in vitro cytotoxicity was assessed using three equine cell lines and the observed phototoxic effect was comparable to that on different highly sensitive human cell lines and significantly influenced by the energy density used although independent of the cell type. The in vivo antitumoural action of photodynamic therapy using hypericin was evaluated on three equine sarcoids in a donkey. Four intratumoural injections were given and the tumours were illuminated daily during 25 days. An 81% reduction in tumour volume was obtained at the end of therapy and 2 months later, a 90% reduction was observed. Further experimental work should be performed, but these results suggest that photodynamic therapy using hypericin has a potential for the non-invasive treatment of equine sarcoids.

Animals↗
PubMed2000

A flexible architecture for constructing and executing tutoring processes.

The tutoring process of conventional case-oriented medical training systems can be characterised as either guided or unguided. In contrast to that, the aim of the system "Docs'n Drugs" is to distinguish between different levels of guidance. The author can realise the tutoring case as a guided, a half guided or an unguided tutoring process. The system architecture distinguishes between an authoring system and a tutoring system. Fundaments of these are the tutoring process model and the case data model. This structure allows the reuse of elements of existing tutoring cases. The tutoring cases can be realised in different languages, e.g. German and English.

Computer-Assisted Instruction↗
PubMed1999

Reverse chromosome painting for the identification of marker chromosomes and complex translocations in leukemia.

BACKGROUND: Chromosome banding techniques and in situ hybridization reveal the majority of chromosomal aberrations. However, difficulties remain in cases of highly contracted chromosomes, poor quality of the metaphases or the presence of markers with the involvement of several chromosomes. Here, it is demonstrated that reverse painting can be applied successfully starting with bone marrow cells from primary acute myelocytic leukemias (AML). METHODS: This was accomplished by culturing the leukemic cells with a cocktail of various growth factors, which yielded sufficient numbers of cells in cycle to harvest chromosomes for sorting. Aberrant chromosomes were flow-sorted and amplified by degenerate oligonucleotide-primed PCR. The resulting products were labeled by nick-translation and hybridized on normal metaphase spreads. RESULTS: Two patients with marker chromosomes in their leukemia cells were analyzed in detail. The hybridization pattern displayed the composition of the aberrant sorted chromosome. Results were compared with conventional cytogenetic analyses that were performed on material obtained from the same aspirate. The reverse-painting technique enabled identification of aberrations that were not detected by conventional cytogenetic analysis. CONCLUSIONS: Primary AML cells can be cultured in vitro, using optimal culture conditions, facilitating the production of high quality flow karyotypes, suitable for sorting of marker chromosomes to produce DOP-PCR derived chromosome painting probes for reverse painting. Valuable additional cytogenetic information can thus be obtained about complex chromosomal rearrangements or structural aberrations that could not be completely resolved by conventional cytogenetic analysis.

Bone Marrow↗
PubMed1999

Neutrophil function capacity to express CD10 is decreased in patients with septic shock.

OBJECTIVE: To evaluate the performance of a newly developed assay to assess neutrophil function capacity. After optimization, the assay was performed on samples derived from patients with septic shock and compared with healthy controls and patients with a systemic viral infection. DESIGN: Prospective evaluation of the performance of a new assay. SETTINGS: Medical intensive care unit, hospital laboratory. PATIENTS: Ten patients with septic shock, ten patients with infectious mononucleosis, and ten healthy controls. MEASUREMENTS AND MAIN RESULTS: We report an assay to assess neutrophil function capacity, in which CD10 membrane expression is measured by FACS before and after in vitro stimulation with Staphylococcus aureus bacteria. This assay evaluates the early activation state of circulating neutrophils and is shown to be of value in diagnosing a sepsis syndrome. First the assay was optimized. As an anticoagulant, sodium-citrate gave the best results. Blood samples must be kept on ice to reduce activation inside the siliconized tube and can be stored in this way for at least 8 hrs without affecting the test results. Kinetic studies showed a maximal expression of CD10 on neutrophils of healthy volunteers after 15 mins of stimulation with S. aureus bacteria. Second, the test was performed on samples derived from ten septic patients and ten patients with infectious mononucleosis. Septic patients had a significantly decreased CD10 expression capacity compared with healthy controls. Patients with infectious mononucleosis have a significantly higher CD10 expression capacity compared with septic patients, but in approximately one-half of them, the expression capacity was below the range found in controls. CONCLUSIONS: These results indicate that in circulating neutrophils, the secretory vesicles have been mobilized completely in patients with septic shock. The assay proves to be of acceptable analytical quality and can be quickly and easily performed. Regarding clinical performance, this assay may be helpful in diagnosing septic shock.

Adolescent↗